Woven wire belt for paper making machines



ly 1937; H. e. SPECHT 2,088,447 wovnu WIRE BELT FOR PAPER MAKINGMACHINES mm lla rc h 23, 1936 2 Sheets-Sheet 1 lllli'm WELL nul - IVENToR.

. HHRRY J T I W ATTORNEYAN July 27,1937.

H. G. SPECHT WOVEN WIRE BELT FOR FAPER MAKING MACHINES Filed Maroh\25,1936 2 SheetS-Sheet 2 r Y aw T5 m n Gw v Patented July 27, 1937 T .UNlTb l g z,oss';4,47' WOVEN WIRE BELT FOR PAPER MAKING MACHINES Harry G.Specht, Montclair, N. J., assignor, by mesne assignments, to 'Enc'orCorporatiom;

Belleville, N. J., a corporation of New Jersey Application March 23,1936, Serial No. 70,527

2 Claims.

fine wire mesh which moves over spaced sup porting rolls and in contactwith suction boxes and rolls. According to the inventions disclosed insaid patents greater strength and flexibility. as well as improveddrainage characteristics and better paper formation surface, wereobtained by providing the warp wires in the form of fiat ribbon likewires which were interwoven with shoot or weft wires of circularcross-section, the knuckles of the weft wires being formed about theflattened surfaces of the warp wires. Also according to theseinventions, a much finer beat up of the woven wire was permitted, withan increase in the fiat knuckle surfaces of the warp wires whereby agreatly increased wearing surface was produced.

It is proposed in the present invention to provide shoot or weft wireswhich will permit of a flatter type of weave, that is, a decreasethickness dimension without sacrifice of strength, and in which the weftknuckles will provide larger surfaces contiguous to the paper formationside and wear side, so that the wire will have a better paper formationsurface and a greatly increased wear surface. To this end it is proposedto provide the shoot or weft wires in the form of pairs of circularcross-section wires arranged side by side.

The invention has application in both regular weave wires, and in twillweave wires in which the warp wires are carried under two and-over oneweft wire to provide longer knuckles and greater wearing surface at theunder side. In the case of twill weave the relatively large paperformation and wear surfaces of the warp and weft wires will make for amuch finer paper formation surface, as distinguished from the usual typeof twill weave in which the paper formation surface had long deepdepressions due to the spacing of the warp knuckles to every third weftwire insteadof to every second weft wire as in the regular weave. Byincreasing the length of the weft knuckles, and at the same timeobtaining a finer beat up due to the ribbon like warp wires, thedepressions are not only decreased in size, but the walls of the meshopenings have less convergence and therefore will 5 provide bettersupport for the paper fibres with less tendency for the fibres to turndown into the mesh openings. 1

According to my invention there will be an increase in the weft knucklesurfaces both in the direction of the weft and in the direction of the 5warp wires, the increase in the direction of the weft wires being due tothe formation of the weft knuckles over the fiat warp wires, and theincrease in the direction of warp being due to the increasedtdimensionof the pair of weft wires in 10 the direction of the warp, asdistinguished from the single circular cross-section weftwires-heretofore employed.

With the above and other objects in view em- .bodiments of the inventionare shown in the accompanying drawings, and these embodiments will behereinafter more fully described with reference thereto, and theinvention will be finally pointed out in the claims.

In the drawings: Fig. 1 is an enlarged plan view of a portion of aregular weave wire belt, according to one illustrated exemplaryembodiment of my invention. Fig, 2 is a longitudinal sectional view,taken along the line 2-2 of Fig. 1.

Fig. 3 is a transverse sectional view, taken along the line 3-3 of Fig.1.

Fig. 4 is an enlarged plan view of a portion of a twill weave wire belt,according to another illustrated exemplary embodiment of my invention.

Fig. 5 is a longitudinal sectional view taken along the line 5-5 of Fig.4.

Fig. 6 is a transverse sectional view, taken along the line 6-6 of Fig.4.

Similar reference characters indicate corresponding parts throughout theseveral figures of the drawings.

Referring to Figs. 1 to 3 of the drawings, the Fourdrinier wire,according to the exemplary embodiment shown therein, comprises warpwires IU of flat ribbon-like form, and. double weft wires ||-ll ofcircular cross-section arranged inside by side relation, and replacingthe usual single circular cross-section weft wire. The upwardly crimpedknuckles of both the warp and weft wires provide the upper paperformation surface, and the downwardly bent knuckles provide the lowerwearing surface. The warp wire is preferably a rolled or drawn bronzewire which is.50 annealed before weaving, and the weft wires arepreferably brass.

In the proper weaving of the wire the warp should control or predominatethe weft. The

stronger warp wires permit of beating the weft Y responding in length tothe distance between wires up to a finer mesh, the flattened warp wiresbeing highly flexible and directly taking the punishment and strainnecessary in this operation. The weft wires, which are shaped by andfollow the action of the warp wires, only indirectly take the strainimposed by the beating up operation, and should not be such as toovercome the predominance or control of the warp wires. Where both thewarp and weft are of the same material, this control is lost to a cer-'tain extent as neither the warp nor the weft will predominate over theother. Other mav terial than bronze and brass may be used for the warpand weft, as for instance stainless steel for the warp and bronze orbrass for the weft.

The dimension of the warp wires are proportioned with respect to theweft wire diameter, the width being such as to provide a relatively widepaper formation and wear surface and the thickness being such as topermit a fine beat up of the weft, and at the same time allow theknuckles of the weft, with a lesser deformation in the crimping of theweft than in the warp, to come into .or very close to the plane of thewarp knuckles. For instance with .009 of an inch diameter weft wires thewidth of the warp wires may be .012 of an inch and the thickness .004 ofan inch. The relative thinness of the flat warp wires, it will be seen,allows beating up a large number of weft wires per inch, while theirrelative wideness gives an area equivalent to or greater than that ofthe largest round warp wire permissible. The edges of the warp wires arepreferably slightly rounded to allow free drainage through the meshopenings.

The cross-sectional width dimension of the double weft wires ll--l l isapproximately twice the thickness dimension, and as the spaced crests ofthe two wires provide a bridging support for the warp knuckles thelatter will have relatively long fiat surfaces in the upper and lowersurface planes of the woven wire, thus producing a relatively flattertype ofweave in which the paper formation and wear surfaces of the warpwires are increased from line contact surfaces, as is the case when theknuckles are formed over single circular cross section weft wires, tosurface contact areas substantially corthe crests of the double weftwires. This is of particular advantage at the beginning of the use ofthe wire as wide contact areas are present both before the knuckles areworn down and after wearing down, so'that an approximately uniform wearsurface is maintained throughout the life of the wire.

The knuckles of the double .weft wires are increased in the weftdirection by being formed over the flat warp wires and are increased inthe warp direction by the double crests of each knuckle. The twodirectional flat knuckles of the warp as well as the two directionalwide knuckles of the weft produce a paper formation surface in which thefibres will be supported by flat contact, as distinguished'from thepoint contact with wires having circular cross-section warp and singlecircular cross-section weft wires. At the same time the fine beat up ofthe weft provides a smooth surface which will support the paper stockwithout the usual tendency to turn down into the mesh and clog it.Withoutsacrificing this support the mesh openings may be of adequatesize to provide full drainage.

The double weft also disposes double the number of weft knuckles on thewear side and as these have substantially flat surfaces in the weft 1direction the wearing life will thereby be greatly increased.

The flat warp wires while providing a much greater tensile strength areat the same time more flexible than circular cross-section wa rp wires,and this in addition to the longknuckles formed over the double. weftwires enables the woven wire to be operated at high speed over rolls fora considerably greater time than heretofore before fatigue sets in.

In the modification shown in Figs. 4 to 6 the Fourdrinier wire is atwill weave,.the warp wires Ill being woven under two pairs and over onepair of the double weft wires li -l I, thus providing very long knuckleson the wear side. I have illustrated and described a preferred andsatisfactory embodiment of my invention, but it will be obvious thatchanges may be made therein, within the spirit and scope thereof, asdefined in the appended claims.

Having thus described my invention what I claim and desire to secure byLetters Patent is:-

1. Woven wire fabric for paper making machines comprising interwovenwarp and weft shoots, each comprising a. pair of weft wires, withknuckles produced in both the warp and weft wires, the warp wiresthroughout their length being of non-circular cross-section elongated inone dimension, said elongated dimension being parallel to the plane ofthe woven wire fabric whereby the weft knuckles cross the elongatedfaces of the warp wires and have their outer projected surfacessubstantially co-extensive transversely with said elongated faces, thepair of weft wires of each shoot being arranged side by side whereby thewarp knuckles cross the spaced crests of said weft wires and have theirouter projecting surfaces substantially co-extensive transversely withthe spaces between said crests.

2. Woven wire fabric for paper making machines comprising interwovenwarp and weft shoots, each comprising a pair of weft wires, withknuckles produced in both the warp and weft wires, the warp wires beingcarried over one and under a plurality of weft shoots, the warp wiresthroughout their length being of noncircular cross-section elongated inone dimension, said elongated dimension being parallel to the plane ofthe woven wire fabric whereby the weft knuckles cross the elongatedfaces of the warp wires and have their outer projected surfacessubstantially co-extensive transversely with said elongated faces, thepair of weft wires of each shoot being arranged side by side whereby thewarp knuckles cross the spaced crests of said weft wires and have theirouter projecting surfaces substantially co-extensive transversely withthe spaces between said crests.

HARRY G. SPECHT.

